JPH06201000A - Five-speed automatic transmission for passenger car - Google Patents

Abstract

PURPOSE: To permit five shifts by use of the same number of friction elements as an existing four-speed automatic transmission so as to compact a five-speed automatic transmission and improve the on-vehicle mountability thereof by installing three planetary gearsets, five friction elements, and one or two one- way clutches in combination with one another. CONSTITUTION: First to third planetary gearsets 10, 20, 30 having respective planetary carriers 12, 22, 32 which mesh with sun gears 11, 21, 31 and ring gears 14, 24, 34 are disposed between an input shaft E and an output shaft S which are contained in a casing. Five friction elements comprising three control clutches C1 -C3 and two control brakes B1 , B2 are disposed between the input shaft E and the output shaft S and two one-way clutches R1 , R2 are also disposed. A torque converter 40 is disposed on the input shaft E and its impeller 41 is connected to an engine M. Therefore, five speeds are made possible with the same number of friction elements as an existing four-speed transmission.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planetary gear unit which is controlled by hydraulically driven friction elements such as a clutch and a brake and which is coupled to a starter coupling device having a slip such as a hydraulic torque converter and a fluid coupling. And an automatic transmission for passenger cars.

[0002]

2. Description of the Prior Art Many of the automatic transmissions of this type currently on the market have a four-speed gear stage, a hydraulic torque converter and two sets of simple planetary gears or Ravigneaux. ) A gear device, five friction elements, and a one-way clutch for facilitating the speed change operation in the power-on state of the 1st / 2nd speed and the 2nd / 1st speed. Very often, torque converters have lock-up clutches to prevent slipping outside of transient conditions and to improve fuel economy.

In addition, most of these transmissions are second speed /
A second one-way clutch is provided in series with this one-way clutch in order to facilitate the shifting operation in the power-on state of the third speed and the third speed / 2nd speed or the third speed / 4th speed and the fourth speed / 3rd speed. And an additional friction element for releasing the one-way clutch at another gear. In addition to planetary gearboxes and torque converters, which often include lockup clutches, these automatic transmissions usually have a number of shifting elements, which are five friction elements and one one-way clutch. Alternatively, six friction elements and two one-way clutches constitute a four-speed gear.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to achieve five gears in a compact enough construction to allow easy replacement with known four-speed automatic transmissions.
An object of the present invention is to provide a higher performance automatic transmission using a more advantageous number of transmission elements with five friction elements and one one-way clutch or five friction elements and two one-way clutches.

[0005]

According to the present invention, there is provided a planet carrier which is arranged between an input shaft and an output shaft aligned in a casing and which carries planet pinions respectively meshing with a sun gear and a ring gear. There is provided an automatic transmission, particularly an automatic transmission for a passenger vehicle, which is composed of the first, second and third planetary gear trains and the five friction elements of three control clutches and two control brakes. Selective actuation of the pairs of friction elements determines various gear ratios between the input and output shafts. The sun gear of the third planetary gear device is fixed to the input shaft, the ring gear of the second planetary gear device and the planet carrier of the third planetary gear device are fixed to the output shaft, and the first A sun gear of a planetary gear is fixed to the casing, and a planet carrier of the first planetary gear and a sun gear of the second planetary gear are rotatably coupled together. The planet carrier of the second planetary gear device is connected to the ring gear of the third planetary gear device and the input shaft via the first and third control clutches, and is rotated by the first control brake. Be blocked. The ring gear of the first planetary gear device is connected to the input shaft via the second control clutch and is prevented from rotating by the second control brake.

By selectively operating a plurality of pairs of the five friction elements, a forward speed 5 speed and a reverse speed 1 speed are formed, and the forward movement is performed by the operation of the first control clutch and the first control brake. First speed, forward second speed by operation of the first control clutch and the second control brake, third forward speed by operation of the first and second control clutches, forward speed by the second and third control clutches 4th speed, forward 5 by operation of the third control clutch and the second control brake
Each reverse speed is set by the operation of the speed and the second control clutch and the first control brake.

In order to facilitate the speed change in the power-on state of the 1st / 2nd speed and the 2nd / 1st speed, the rotation of the planetary carrier of the second planetary gear device in the direction opposite to the rotation direction of the input shaft is performed. To prevent this, the automatic transmission is provided with a first one-way clutch provided in parallel with the first control brake, and the first speed traction mode is set only by engagement of the first control clutch. .

Similarly, in order to facilitate the shifting in the power-on state of the fourth speed / 5th speed and the fifth speed / 4th speed, the automatic transmission is provided with the input shaft of the ring gear of the first planetary gear device. A second one-way clutch provided in parallel with the second control clutch in order to prevent rotation at a rotational speed exceeding the rotational speed of the third control clutch. Only set by.

The features and advantages of the present invention will become more apparent in the following description with reference to the accompanying drawings.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, an automatic transmission according to the present invention has an input shaft E and an output shaft S which are accommodated in a casing in an aligned state. The first planetary gear device 10 includes a planetary pinion 1 meshed with a sun gear 11 and a ring gear 14.
It has a planet carrier (pinion carrier) 12 carrying 3 The second planetary gear device 20 includes a sun gear 21.
And a planet carrier 22 carrying a planet pinion 23 meshing with the ring gear 24. The third planetary gear device 30 has a planet carrier 32 that carries a planet pinion 33 that meshes with a sun gear 31 and a ring gear 34. The sun gear 31 is fixed to the input shaft E, and the ring gear 24 and the planet carrier 32 are fixed to the output shaft S. The sun gear 11 is fixed to the casing, and the planet carrier 12 and the sun gear 21 are fixedly coupled to each other so as to rotate together.

The first control clutch C1 is inserted between the planet carrier 22 and the ring gear 34, the second control clutch C2 is inserted between the input shaft E and the ring gear 14, and the third control clutch C1 is inserted. C3 is inserted between the input shaft E and the planet carrier 22. First control brake B1
Is provided to prevent the rotation of the planet carrier 22, and the second control brake B2 is provided to prevent the rotation of the ring gear 14. In addition, the first one-way clutch R1 may be provided in parallel with the first control brake B1 in order to prevent the rotation of the input shaft E of the planet carrier 22 in the opposite direction.

The transmission also includes a torque converter 40.
Is provided. The torque converter 40 includes an impeller 41 connected to the engine M, a turbine 42 connected to the input shaft E, a stator 43, a one-way clutch 44, a lockup clutch 45, and a torsional vibration damping damper 46. is doing.

The operation will be described below.

At the first speed, the first control clutch C1 and the first control brake B1 are engaged. This prevents the planet carrier 22 and the ring gear 34 from rotating. Therefore, the rotation is transmitted by the planetary gear device 30 having the reduced speed ratio because the ring gear 34 is in the locked state. The sun gear 21 and the planet carrier 12 are rotated in opposite directions by the second planetary gear unit 20.

At the second speed, the first control clutch C1 and the second brake B2 are engaged. This prevents the planet carrier 12 and the sun gear 21 from rotating. The planet carrier 22 and the ring gear 34 are driven at a reduced speed. The rotation is transmitted at the first intermediate reduction gear ratio of the third planetary gear device 30.

At the third speed, the first and second clutches C1 and C2 are engaged. As a result, the planet carrier 12 and the sun gear 21 are rotationally driven by the locked sun gear at the speed reduction ratio G of the first planetary gear device 10. The planet carrier 22 and the ring gear 34 are driven at high speed. The rotation is transmitted at the second intermediate reduction gear ratio of the third planetary gear device 30.

At the fourth speed, the second and third clutches C2 and C3 are engaged. The planet carrier 12 and the sun gear 21 are driven at a reduction ratio G. Therefore, the rotation is transmitted at the intermediate overdrive ratio of the second planetary gear device 20.

At the fifth speed, the third control clutch C3 and the second control brake B2 are engaged. The planet carrier 12 and the sun gear 21 are prevented from rotating. Therefore, rotation is transmitted by the locked sun gear at the overall overdrive ratio of the second planetary gear set.

When traveling in reverse, the second control clutch C
2 and the first control brake B1 are engaged. The planet carrier 12 and the sun gear 21 are driven at a reduction ratio G. The planet carrier 22 is prevented from rotating. The rotation depends on the reduction ratio G of the second planetary gear set due to the locked planet carrier.
And the reverse gear ratio of the gear set 20.

The one-way clutch R1 prevents the planet carrier 22 from rotating in the direction opposite to the rotation direction of the input shaft E, and exhibits the same effect as when the first control brake B1 is engaged in the first speed gear stage. Produces lower engine braking. Also, this one-way clutch R1
A free wheel is realized at other gears. The upshift of the 1st / 2nd speed and the downshift of the 2nd / 1st are performed simply by engaging and releasing the second control brake B2, whereas the traction mode in the 1st is simply the first control clutch. It is set by the conclusion of C1.
Therefore, control is easy.

FIG. 2 is a table showing the selected state of the friction element at each gear. As is clear from this table, the shift operation from each shift stage to the next shift stage is performed only by changing one of the two engaged friction elements in all shift ranges. The shifting action with only this single element transition provides the most operational possibilities.

In this table, the additional motions provided by the one-way clutches R1 and R2 for the 1st and 4th speeds, respectively, the operation of B1 for the 1st speed and the operation of C2 for the 4th speed are shown in parentheses. However, these operations will be described later with reference to FIG.

FIG. 3 is a diagram showing the rotational speeds of the second and third planetary gear units 20 and 30 when the rotational speed of the input shaft E is used as a comparison unit. As is clear from the figure, all rates of occurrence were within very reasonable limits.

In addition to the above, there are at least two states. That is, the input shaft E rotates freely, the output shaft S is prevented from rotating by the engagement of the first and second control brakes B1 and B2, and the first and third control clutches C1 and C3. It is an intermediate direct drive range between the third speed and the fourth speed which is set by engagement of.

Table 1 below shows three examples of gear ratios as a function of the number of teeth of the first, second and third planetary gear sets 10, 20, 30. The gear ratio is given as the ratio of the rotation speed of the output shaft S to the constant rotation speed of the input shaft E, assuming that the torque converter 40 does not slip. The step ratio indicates the actual ratio between successive shift speeds. The gear ratio width is the actual ratio between the lowest speed gear and the highest gear speed, the forward gear ratio width is the ratio between the fifth speed and the first speed, and the reverse gear ratio width is the fifth speed and the reverse speed. It is a ratio between gear reduction ratios. The direct drive between the 3rd and 4th gear is not used.

[0026]

[Table 1] This series of gear ratios is perfectly adapted to a five-speed transmission and shows outstanding selectivity. Note that the above gear ratio can be changed as appropriate, and a simpler replacement of the planetary gear device provides more excellent selectivity.

FIG. 4 shows a modification of the transmission shown in FIG. In this modified example, the second one-way clutch R2 is provided in parallel with the second control clutch C2 to prevent the ring gear 14 from rotating at a higher rotational speed than the input shaft E. In the fourth speed traction mode, the input shaft E is driven without driving the sun gear 21 and the planet carrier 12. Second control clutch C
The release of 2 enables one-way drive via the one-way clutch R2 and deactivates the engine brake. The 4th / 5th gear shift-up and the 5th / 4th gear shift-down in the power-on state can be performed simply by engaging and releasing the second control brake B2, thus facilitating the control. Referring to the rotational speed diagram of FIG. 3, the sun gear 21 and the planet carrier 12 do not exceed the reduction ratio G, and therefore the rotational speed of the ring gear 14 does not exceed the rotational speed of the input shaft E. Recognize. This allows the one-way clutch R2
It is not necessary to provide an additional control clutch in series with the one-way clutch in order to disengage, and there is an advantage that only five friction elements and two one-way clutches can be used as the speed-changing elements for shifting the fifth speed. .

Another variant of the invention is shown in FIG. One planetary gear set, for example the second planetary gear set of FIG. 1, is replaced by a planetary gear set 20a with a stepped planet pinion. Planetary gear device 20a
Has a planet carrier 22a carrying a planet pinion 23a having two sets of gear teeth, the gear teeth 23b of the planet pinion mesh with the sun gear 21a, and the gear teeth 23c mesh with the ring gear 24a. .

The operation is similar to that of FIG. In the case of Example 3 above, by setting the number of teeth of the planetary gear device of FIG. 5 as follows, it is possible to obtain substantially the same gear ratio, step ratio, and gear ratio width.

Sun gear 21a 39 Ring gear 24a 87 Planetary pinion 23b 20 Planetary pinion 23c 27 The present invention is not limited to the above-mentioned embodiments illustrated for the purpose of explanation, but includes all modifications and alterations. is there. In particular, the use of direct drive by changing the arrangement of the planetary gear units 10, 20, 30 and the reduction ratio G and / or engaging the first and third control clutches C1 and C3 at the same time is claimed. The present invention belongs to the scope of the invention described in the scope of.

[0031]

As described above, according to the present invention, the same number of friction elements as those of the conventional 4-speed automatic transmission can be used to change gears in five speed stages, and the device can be used in almost the same manner as the 4-speed automatic transmission. Since the size can be reduced, it can be easily mounted on a vehicle equipped with a 4-speed automatic transmission.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an automatic transmission according to an embodiment of the present invention, which includes a first one-way clutch for 1st / 2nd speed and 2nd / 1st speed shift.

FIG. 2 is a diagram showing a friction element selection table.

FIG. 3 is a diagram showing the number of rotations in the second and third planetary gear devices.

4 is a schematic diagram showing a modified example of the automatic transmission of FIG. 1 provided with a second one-way clutch for shifting in the power-on state of the fourth speed / 5th speed and the fifth speed / 4th speed.

FIG. 5 is a diagram showing a modification of FIG. 1 provided with a planetary gear device having a stepped planetary pinion.

[Explanation of symbols]

 10 First Planetary Gear Device 11 Sun Gear 12 Planetary Carrier 13 Planetary Pinion 14 Ring Gear 20 Second Planetary Gear Device 21 Sun Gear 22 Planetary Carrier 23 Planetary Pinion 24 Ring Gear 30 Third Planetary Gear Device 31 Sun Gear 32 Planetary Carrier 33 Planetary Planet 33 Pinion 34 Ring gear 40 Torque converter C1 First control clutch C2 Second control clutch C3 Third control clutch B1 First control brake B2 Second control brake R1 First one-way clutch R2 Second one-way clutch

Claims (3)

[Claims] 1. A first, second and third planetary carrier having a planetary carrier disposed between an input shaft and an output shaft aligned in a casing and carrying planetary pinions respectively meshing with a sun gear and a ring gear. It consists of a planetary gear train and five friction elements of three control clutches and two control brakes, and determines the various gear ratios between the input and output shafts by the selective operation of the pairs of friction elements. The sun gear of the third planetary gear device is fixed to the input shaft, the ring gear of the second planetary gear device and the planet carrier of the third planetary gear device are fixed to the output shaft, The sun gear of the first planetary gear unit is fixed to the casing, and the planet carrier of the first planetary gear unit and the sun gear of the second planetary gear unit are coupled to rotate together, and the second The planet carrier of the planetary gear device is connected to the ring gear of the third planetary gear device and the input shaft through first and third control clutches, and is prevented from rotating by the first control brake. Placed,
The ring gear of the first planetary gear device is connected to the input shaft via the second control clutch and is configured to be blocked from rotation by the second control brake. By selectively operating the pair, a forward speed 5 speed and a reverse speed 1 speed are formed, and by the operation of the first control clutch and the first control brake, the forward speed 1 speed, the first control clutch and the first control clutch 2nd forward speed by the operation of the second control brake, 3rd forward speed by the operation of said first and second control clutches, 4th forward speed by the operation of said second and third control clutches, said third control clutch and said A vehicle, particularly a passenger car, characterized in that the fifth speed is set forward by the operation of the second control brake, and the reverse speeds are set by the operations of the second control clutch and the first control brake. Automatic transmission. 2. A first one-way clutch provided in parallel with the first control brake in a direction that prevents rotation of the planet carrier of the second planetary gear device in a direction opposite to the rotation direction of the input shaft. The automatic transmission according to claim 1, wherein the first-speed traction mode is set only by engaging the first control clutch. 3. A second one-way provided in parallel with the second control clutch so as to prevent rotation of the ring gear of the first planetary gear device at a rotational speed exceeding the rotational speed of the input shaft. The automatic transmission according to claim 1, further comprising a clutch, wherein a traction mode of a fourth speed is set only by engagement of the third control clutch.